UNIT#04 LIQUIDS Flashcards
CHCl3 exist in a liquid state due to;
Dipole-Dipole Forces
The highest boiling point among the following is for:
Br2
(Intermolecular Force⬆ Vapour Pressure⬇ Boiling Point⬆)
➡has a stronger London Dispersion force due to molar mass
In NH3, dominant Van der Waal’s force among the following is:
Hydrogen Bonding
Liquids have no definite shape; it is because:
The molecules of the liquid are in constant motion by sliding over each other
Propanone is miscible in water due to:
➡Both are polar molecules
➡Hydrogen bonding between them
➡Dipole-Dipole attraction between them
Strong dipole-dipole forces among the liquid molecules are responsible for:
The very high heat of vaporization
Which one of the following arrangements usually represents the correct order of increasing interactions?
London Forces, Dipole-Dipole, Hydrogen Bonding
Which of the following has the strongest intermolecular forces of attraction
Iodine
(Molar mass⬆ Polarizability⬆ London Dispersion Force)
The forces which are present between the ions and water molecules are known as:
Ion dipole forces
Forces of attraction, which may be present between all kinds of atoms and molecules are:
London Dispersion forces
The attractive forces between the partially positive end of one molecule and the partial negative end of another molecule are called:
Dipole-Dipole forces
Liquid gets the shape of the container when it is poured into it. Which one of the following reasons justifies it
The liquid does not have a definite shape
The nature of bonding affects the properties like:
➡Solubility
➡Melting, Boiling Points and isomerism
➡Reaction Kinetics
The Vapour pressure of water is 4.579 torr and 9.209 torrs at 10° C, so the increase in vapour pressure from 0° C to 10° C is 4.630 torr. What will be the change in vapour pressure from 90° C to 100° C?
> 4.630 torr
Which of the following has the highest vapour pressure?
Iso-pentane➡has the weakest force of attraction
(V.P α 1/ Intermolecular Force)
The boiling point of water would be highest at:
Gawadar
Which one is false for evaporation:
Exothermic
(Evaporation is an endothermic process)
Vapour pressure of water at 100° C is:
760 mm Hg
The conversion of vapours back into other liquid states is called:
Condensation
Which one of the following has the highest volatility
Diethyl Ether
(L.D.F⬆ V.P⬇ Volatility⬆)
In order to mention the boiling point of water at 110° C, the external pressure should be:
Between 760 torr and 1200 torr
(Boiling point of liquid α External Pressure
The boiling point increases down the zero group element due to:
London Forces
If we provide a very high amount of heat to a liquid its boiling point will:
Remain constant
Evaporation is designated as a colling process because of the reason:
High energy molecules leave behind the low energy molecules and cause cooling
The Vapour pressure of a liquid depends upon the following:
Temperature and the inter-molecular forces
(➡V.P α Temperature
➡ V.P α 1/ Intermolecular Forces)
At 1atm pressure, liquid 1 has the boiling point less than liquid 2, what can we predict about both the liquids?
➡Liquid 1 has high vapour pressure than the liquid 2
➡Liquid 1 has a weak intermolecular force of attraction than the liquid 2
➡Liquid 1 is more volatile than the liquid 2
The distillation of a solution under reduced pressure is called:
Vacuum Distillation
A pressure cooker reduces cooking time because:
The boiling point of water rises
Molar heat of vaporization of water is:
➡40.6 kJ/mol
The rate of evaporation of a liquid depends upon:
➡Surface area of liquid
➡Temperature
➡Intermolecular Forces
Which one of the following would cause severe burning
Steam at 100° C
The boiling point of a liquid is the temperature at which
The vapour pressure of the liquid is equal to the atmospheric pressure
The strength of hydrogen bonding is:
20 times less than a covalent bond
When ammonia is dissolved in water, a number of hydrogen bonds formed with ammonia
1
(as there is one lone pair)
Lower alcohols are soluble in water because:
Intermolecular Hydrogen bonding
The strongest H-bond is:
F—H
When two ice cubes are passed over each other, they unite to form one cube. This is due to:
Hydrogen Bond Formation
Which of the following can form hydrogen bonding among its molecules more prominently
CH3OH
Hydrogen bonding is involved in:
➡Solubility
➡Cleasnsing action of detergents
➡Biological molecules
When water freezes at 0° C its density decreases due to:
Empty space present in the structure of ice
The correct order of boiling point of the given liquids is:
H2O>HF>NH3>HCl
At 1489 mmHg, water will boil at:
120° C
Ice is less dense than water at:
0° C
In a crystal lattice of ice, each O-atom of the water molecule is attached to:
Four H-atom
What is the reason that the ice at 0° C occupies more volume than water:
Empty spaces
Water has maximum density at:
4° C
DNA molecule is double-stranded, in which two chains of DNA are twisted around each other by:
Hydrogen Bond
Which of the following substances exhibits hydrogen bonding?
NH3
In the ‘H-F’ bond electronegativity difference is 2.0. What is the type of this bond?
Polar covalent bond
The boiling point of water is higher than petrol because intermolecular forces in water are:
Stronger than petrol
Metallic conduction involves the relatively free movement of their _____ throughout the metallic lattice:
Electrons
Which type of force is present in gasoline?
London Dispersion forces
Which one of the following hydrogen bonds is stronger than the other?
F-H——F-H
An intermolecular force of attraction X is relatively stronger than the other intermolecular forces, it stabilizes α-helix and β-pleated sheets of proteins. The double helical structure of DNA is also stabilized by this force of attraction. Identify X
Hydrogen Bonding
At higher altitudes, the boiling point of water is less than 100° C, this is because of:
Lower atmospheric pressure
Steam causes more severe burns than boiling water. It is due to:
High Latent Heat of vaporization
According to Watson and Crick’s model of DNA, the DNA molecule consists of the double helix. What type of forces is responsible to keep two strands of DNA together?
Hydrogen Bonding
CO2 and SO2 both are tri-atomic molecules but the heat of vaporization of SO2 is greater than that of CO2 due to:
SO2 is polar and CO2 is non-polar
Which of the following has the lowest vapour pressure at 20° C?
Water
Which of the following is not a molecular solid?
Bromine
The distillation which is carried out under reduced pressure is called as
Vaccum Distillation
In which of the following water evaporate earlier
Sauce pan
Conversion of water into steam is a
Spontaneous reaction
On which factors the vapour pressure of a substance does not depend
Surface Area
How many times of covalent bond is stronger than hydrogen bond
20 times
Separation of components of liquid on the basis of their boiling point called as
Fractional Distillation
Which instrument is used to measure the vapour pressure of a liquid
Manometer
Which of the following has highest vapour pressure
Diethyl ether
When heat provided to a liquid it causes it to
Expand
Which of the following intermolecular forces are present between Octane molecule
London Dispersion froces
Which of the following forces ability to form strong bonds
H-bond